Tumor infiltrating lymphocytes (TILs) are a part of the dynamic immune microenvironment. Increased levels of TILs are associated with better clinical outcomes in diverse human neoplasms, including melanoma, colorectal cancer, triple-negative carcinomas, and non-small cell lung cancer (NSCLC). Clinical trials with immune checkpoint inhibitors report significant increase in TILs in responders to treatment in follow up biopsies. However, since biopsies are invasive, time consuming, expensive, and may expose a patient to significant side effects, it would be beneficial to more accurately and non-invasively determine which patients are more likely to exhibit increased levels of TILs.